The present invention relates to a portable auger for transporting particulate material, and more particularly, to a portable auger having a center drive connectable to a power take-off (PTO) of a tractor or other power source.
Portable augers having central drive linkages are well known in the art. Center drive portable augers include an internal gear box mounted in line with an auger flighting such that the gear box is totally enclosed within an auger tube. Typically, the diameter of the auger tube around the internal gear box is expanded to facilitate easy passage of the particulate material past the internal gear box. Additionally, a telescoping power take-off or other power source can be used on either side of the auger tube for convenience of the operator. However, internal gear boxes often leak oil into and contaminate the particulate material. Also, friction of the particulate material past the internal gear box causes the gear box to run hot thereby decreasing the effective life of the gear box and again leading to oil leakages.
External gear boxes are known for "top driven" auger flights. In top driven augers the gear box is positioned on an external surface of the auger tube near the feed end since the feed end is closer to the power-take-off (PTO) of the tractor. An output shaft extends from the external gear box up the entire length of the auger tube to the discharge end thereof. Typically, a chain and sprocket at the discharge end of the auger tube connects the output shaft to the drive shaft of the auger flighting.
External gear boxes have also been used with "bottom driven" auger flights wherein a separate feed auger is provided to dispense particulate material into a main auger tube. In such an arrangement, the main auger tube typically is bottom driven through the external gear box and the feed auger is typically top driven through an external gear linkage.